ALERT For The Potential Of Dense Fog As Cloud Bases Drop From Upper Elevations Into Middle Elevations By Wednesday Morning For Locations Along & North Of The High Knob Massif-Tennessee Valley Divide. Caution For Travelers Is Advised.
A redevelopment of showers, with dropping cloud bases, on a northerly wind shift is expected into the predawn-morning hours of Wednesday. Conditions will continue to be cooler than average for this time of year, especially for locations along and north of the High Knob Massif and Tennessee Valley Divide.
Overnight Into Tuesday Morning
Showers developing. Thunder possible. SSE-SSW winds increasing to 5-15 mph, with higher gusts, along middle elevation mountain ridges-plateaus. SSW to SW winds increasing to 10-20 mph, with higher gusts, along mountain ridges above 2700 feet. Temperatures widespread in the 40s to lower 50s.
Tuesday Afternoon
Showers & thunderstorms becoming likely. Locally heavy rainfall. SW winds 5-15 mph, with higher gusts, becoming northerly. Temperatures varying from the 50s to middle 60s ( coolest in upper elevations ). Dense fog across upper elevations, with patchy fog in other locations.
Tuesday Night Into Wednesday Morning
Chance of evening showers, then showers becoming likely by the predawn-morning. Dense fog possible along middle-upper elevation ridges-plateaus. N-NE winds at generally less than 10 mph. Temperatures widespread in the 40s to lower-middle 50s.
Wednesday Afternoon
Cloudy & chilly. Chance of rain. Low clouds. Winds NNE-ENE at 5-10 mph, with higher gusts along middle to upper elevation mountain ridges-plateaus. Temperatures in the upper 40s to mid-upper 50s ( coolest in upper elevations ).
Wednesday Night Into Thursday Morning
Low clouds. Chance of showers & drizzle. Chilly. Winds NE to ESE at generally less than 10 mph. Temperatures in the 40s to around 50 degrees.
Weather Discussion For May 16-18
Late Tuesday PM Update
Another cooler than normal day for this time of year once again featured temperatures struggling to break 60 degrees in locations along and north of the High Knob Massif.
Nora 4 SSE – NWS Station In Middle Elevations
Afternoon MAXS reached 60 degrees at Nora 4 SSE and 63 degrees in Clintwood ( with 0.41″ of total rainfall / 5.53″ in May ).
Black Mountain MesoNET
Tuesday PM ( May 17 ) temperatures remained in the 50s for places above 2700 feet in elevation, despite a continuation of southerly air flow. A shift to northerly wind direction is delayed on latest model runs until the predawn-morning hours of Wednesday.
High Knob Massif Webcam – University Of Virginia’s College At Wise
Following mid-morning to early afternoon showers, low clouds, and areas of fog some welcomed early evening breaks in the overcast have developed above Wise.
Temperatures are expected to cool some on Wednesday with northerly flow for locations along and north of the High Knob Massif and Tennessee Valley Divide.
Previous Discussion
A cold & frosty morning greeted the new work week into Monday with WIDESPREAD ( not patchy ) frost observed throughout the mountain valleys and hollows of central-northern Wise and Dickenson counties.
Skies became mostly clear into Sunday night ( below ) with dewpoints below freezing at middle-upper elevations.
High Knob Massif Webcam – University Of Virginia’s College At Wise
Freezing temperatures were even reported into portions of the typically milder Clinch River Valley, with 32 degrees and some minor plant damage observed in The Pines section near the community of Dungannon into Monday morning.
Why would this not occur, with dewpoints in the 20s to around 30 degrees from the elevation of Norton-Wise on upward under decreasing winds and mostly clear skies.
MIN temperatures varied from the upper 20s to lower 30s in many valleys, with an official MIN of 33 degrees observed in Clintwood. The MIN reached 30 degrees in Norton.
*NOTE for those asking, temperatures reported by WCYB are not located in Clintwood but are in the South of the Mountain area in the Ramey Flats community ( north of the Pound River ). This site tends to be warmer on cold air drainage nights than valleys such as the Holly Creek Valley ( Clintwood ) and Georges Fork area.
The Weatherbug station at Norton Elementary School is not “officially” online and has been reportedly flagged by AWS for a temperature error that seems to be most pronounced ( but likely exists all the time ) during nights with cold air drainage into the Norton valley.
High Knob Massif Webcam – University Of Virginia’s College At Wise
Mid-high cloud did increase rapidly into Monday morning such that day-time MAX temps into the afternoon remained cooler than I had anticipated at lower-middle elevations along and north of the High Knob Massif.
Nora 4 SSE – NWS Site In The Middle Elevations
It was a struggle for temperatures to reach into the 50s from Norton-Wise to Clintwood and the adjacent ridge communities ( 57 degrees being obtained in Clintwood ).
NAM 12 KM Model Rainfall Forecast Next 84-Hours
While there are some significant differences in model forecast rainfall amounts during the next few days, the general pattern will be damp and cooler than normal for this time of year.
GFS Model Rainfall Forecast Next 84-Hours
The high resolution NAM Model is looking particularly nasty for locations along and north of the High Knob Massif for Tuesday and Wednesday, with low cloud bases developing on northerly upslope flow. I have already posted an ALERT for the potential of DENSE FOG at middle-upper elevations for later Tuesday into Wednesday morning. Stay tuned for updates to see if this may need to be changed or extended.
*The above requires advance warning since travelers along U.S. 23, for example, tend to run from no fog into dense fog upon driving up Indian Creek Mountain onto the Wise Plateau from the north, and from Powell Valley toward Little Stone Mountain Gap and the Overlook area from the south. Rapid drops in visibility upon going into clouds are very dangerous for motorists unaware.
